Since the end of 1980s when Baibich et al observed the giant magnetoresistance (GMR) effect in a magnetic multilayered system, the study of the laminated structure system composed of magnetic layer/non-magnetic layer/magnetic layer has attracted a lot of interest from scientific researchers. Such magnetic element with a giant magnetoresistance effect can not only be widely applied to the field of a magnetic sensor, magnetic record/read head, but also be developed into a radiation-resist and non-volatile magnetic random access memory (MRAM). In recent years, some research groups have proposed that magnetic memory cell can also be designed for computation, i.e., a magnetic logic concept. A logic function is usually realized through two steps of selection and execution of logic operation. Such logic device can become a programmable logic device and a memory device of an instantaneous state electronic output as well. For example, in 2000, William C. Black, Jr. and B. Das from Iowa State University proposed a magnetic logic based on magnetoresistance effect. Two years later, Siemens Research Co. in Germany, demonstrated a reconfigurable magnetic logic element through experiments. Shortly afterwards, Berlin Paul Drude Institute proposed a simpler method to realize switching of various computing elements between different logic states (A. Ney, C. Pampuch, R. Koch and K. H. Pioog, [Nature] vol. 425, pages 485-487 (2003)). Its logic core unit is constituted of a magnetic tunnel junction, and its operating mode diagram and sectional structure diagram is shown in FIGS. 1a and 1b, respectively. Although there are only two output numerical values (0 and 1) in the magnetoresistance element, four different initial states do exist, of which two are parallel states and the other two are counter-parallel states. Thus, different logic states can be configured. Such a single logic element can show the following basic logic functions, “AND” function, “OR” function, “NAND” function and “NOR” function.
However, all the input signal lines in current techniques are disposed on the magnetic multilayers, and the effective magnetic field acting on the magnetic multilayered cell is small, leading to a large operation current. Meanwhile, non-uniform spatial distribution of the magnetic fields will bring an adverse effect. Moreover, the shape of magnetic multilayered cells used in the prior art is a non-closed geometrical structure, such as square, rectangle, circle and ellipse. Such a non-closed structure will bring high demagnetization fields and shape anisotropy under high density and small size, leading to increasing the reversal field of magnetic free layer, and further increasing working current and power consumption for the logic cell. Meanwhile, the vortex magnetic domains are probably produced, resulting in an adverse effect to the uniformity and consistency of the magnetic and electrical properties of the logic element.